The lord chancellor has brought a colourful Cabinet career to an end by announcing his retirement from government.

Lord Irvine spent over six years in the post but felt the time was right to step down having become a regular target of the tabloids.

Tony Blair's mentor also saw his three-pronged job as head of the judiciary, the House of Lords and a government department come under fire from the European courts.

The timing of the announcement paved the way for his departmental responsibilities to be revamped into the new Department for Constitutional Affairs.

The 62 year-old peer could return to legal practice where he was a successful judge, or retire to make the most of his £200,000 per annum pension, the subject of much newspaper opprobrium.

In his letter to the prime minister on Thursday, Lord Irvine also took a final swipe at home secretary David Blunkett, with whom he has clashed over the powers of unelected judges.

"I believe the office of lord chancellor has been of great historic value in our constitutional arrangements, especially in upholding the independence of the judiciary," he said in his resignation letter.